Wake up to sleep: The effects of lacosamide on daytime sleepiness in adults with epilepsy

Abstract

Objective: The objective of the study was to investigate the effects of lacosamide (LCM) on daytime sleepiness ascertained by the Epworth Sleepiness Scale (ESS) in adults with focal epilepsy in a randomized, controlled design.

Methods: Subjects taking ≤2 AEDs for ≥4weeks underwent polysomnography with EEG followed by the maintenance of wakefulness test (MWT) and completed the ESS and other patient-reported outcomes (PROs) at baseline, LCM 200mg/day, and LCM 400mg/day (Visit 4; V4). Primary endpoint was ESS change (V4 to baseline) between LCM and placebo. Noninferiority test on ESS used a one-sided t-test based on a hypothesized difference of 4-point change between groups. Superiority test used a two-sided t-test to investigate the difference in change in PROs and MWT mean sleep latency (MSL) between groups. Fifty-five subjects provided 80% power to show noninferiority of LCM assuming 10% dropout.

Results: Fifty-two subjects (mean age: 43.5±13.2years, 69% female, median monthly seizure frequency: 1 [0, 4.0]) participated. Baseline group characteristics including age, sex, ethnicity, standardized AED dose, seizure frequency, and ESS were similar. Abnormal baseline ESS scores were found in 35% of subjects. Noninferiority test found a ≤4-point increase in ESS (mean [95% CI]) in LCM subjects vs. placebo (-1.2 [-2.9, 0.53] vs. -1.1 [-5.2, 3.0], p=0.027) at V4. No significant difference in change in PROs, MSL, seizure frequency, or AED standardized dose was observed between groups.

Significance: Our interventional trial found that LCM is not a major contributor to daytime sleepiness based on subjective and objective measures. Inclusion of sleepiness measures in AED trials is warranted given the high prevalence of sleep-wake complaints in people with epilepsy.

Keywords: Daytime sleepiness; Epworth Sleepiness Scale; Lacosamide; Maintenance of wakefulness test; Polysomnography; Quality of life.